Projects

Living on the edge – Lesser black-backed gulls foraging and breeding at a coastal-urban interface
01/01/2018
- 30/06/2020

Abstract

Lesser black-backed gulls once successfully adapted to anthropogenic environments, indicating a high degree of behavioural plasticity. They are also considered to be generalist feeders with a wide ecological niche. But most individuals do not exploit the complete range of habitats and resources that are available, they rather specialize. However, the adaptive significance of such specialization likely depends on the predictability of the environment, which at current becomes increasingly unreliable - among others due to human-induced environmental changes.
The PhD project aims at investigating how reproductive decisions vary with the ability of an individual to respond to environmental and anthropogenic changes, and how the costs and benefits of individual specialisation relate to trade-offs throughout the annual cycle (including migration, nest-site selection and reproduction). This will be studied in field experiments via large scale behavioural observations of individually marked (colour-ringed) birds in collaboration with the Research Institute for Nature and Forest (INBO). This will be combined with the implementation of state-of-the-art GPS tracking devices that collect detailed information about individual movements and behaviour 24h/24h via the high tech sensor network (LifeWatch Infrastructure) in collaboration with Flanders Marine Institute (VLIZ).

Researcher(s)

Research team(s)

Assessing the adverse effects of Perfluoralkyl compounds on birds: an integrated field and laboratory approach using passerine birds as model system
01/10/2017
- 30/09/2020

Abstract

Perfluoroalkyl acids (PFAAs) are substances which have been produced for more than five decades. Their unique properties of repelling both water and oil, make them suitable for many industrial and consumer applications such as water and dirt repellents for cloths and carpets, active components in firefighting foams or precursors in Teflon® production. Its extended use, together with their high persistence, resulted in a global contamination of the environment, wildlife and even humans. This ubiquity contrasts sharply with the limited information about their effects on organisms. With this study I will contribute to finding answers to fill some of the most important knowledge gaps in the toxicity mechanisms of these compounds. For this purpose, I will use two model bird species: great tits (Parus major) and canaries (Serinus canaria). Firstly, I will study the PFAAs exposure levels and the fitness consequences in free-living great tits along a PFAAs gradient from a fluorichemical plant in Antwerp, Belgium. Secondly, I will reproduce the exposure levels in captive canaries in order to replicate the results, found in the field, in a more controlled environment. The studied biomarkers will cover several levels of biological organization, from molecular to individual responses. As a result of my study, the PFAAs toxicity mechanisms will be better understood and their impact at an individual and population level can be more accurately forecasted.

Abstract

Ecosystems around the globe are heavily affected by anthropogenic influences, threatening especially long-lived organisms like seabirds. Besides climate-change-induced shifts in the marine food web, many seabirds get killed as bycatch in fisheries, but fishery discards are also valuable food. Previous research has shown that even in dietary generalists individual birds can be specialised on food sources. This can be linked to personality (e.g. whether birds are bold or shy), age or sex, potentially making fishing vessels more attractive for some individuals than others. In this proposal, I aim to 1) explore among-individual differences in foraging behaviour, diet and interactions with fishing vessels in northern fulmars (NF; Fulmarus glacialis), and whether these are related to the birds' personality, age and sex as well as offspring growth, physiology and survival, thereby comparing NF from the North and South of Iceland as these populations experience different oceanographic conditions and population trends; 2) as an additional step compare the foraging behaviour of Icelandic NF with that of their southern counterparts, making use of existing data from southern fulmars (F. glacialoides), which breed at a similar latitude as Iceland, yet experience different ecological conditions (lower temperatures, sea ice, no fisheries). This project will deliver fundamental information about individual specialisation in long-lived seabirds and is highly relevant for species conservation.

Research team(s)

Abstract

Parental care increases offspring survival, but comes at a cost for the parents. Parents are therefore presented with a trade-off between increased investment in current offspring and resource allocation into self-maintenance and future reproductive success. Thus to optimise their reproductive decisions, parents have to take numerous factors into account that relate to their own intrinsic capacity as well as to aspects of their social and ecological environment. With my research I aim to increase our understanding of (1) how reproductive decisions are related to environmental variation in food availability and food accessibility. In particular, I want to study whether and how individual specialisation in resource use constraints parents to comply their offspring's need; (2) how individual decisions depend on the partner, and how efficient withinpair coordination and equality in reproductive investment is achieved to ultimately maximise reproductive success; (3) how intrinsic changes, such as occur in the context of senescence, influence reproductive strategies - via changes in foraging performance and residual reproductive value. To answer these questions, I will study a wild population of individually marked Lesser black-backed gulls, a long-lived migratory seabird species with a high level of inter-individual variation in resource use. I will make use of state-of-the-art GPS devices that allow detailed measurements of parental effort and parental decision rules.

Researcher(s)

Research team(s)

The female perspective of personality variation in a wild songbird: integrating female competition within life history
01/10/2017
- 30/09/2019

Abstract

Individual differences in the expression of traits that improve competitive ability ("competitive traits"; e.g. aggression, ornaments) might play a major role in life history trade-offs, but this is rarely examined in females. At the same time, it has become increasingly clear that individuals often consistently differ in a whole suite of behavioural traits, known as personality. This highlights that behavioural traits (like aggression) should not be studied in isolation given they might not be able to evolve independently under selection. Understanding the selective forces acting on competitive traits in females hence requires their integration within both a personality and life history framework, which will be done here for the first time. Using the great tit (a songbird species) as a model, I will examine whether females consistently differ in a wide variety of ecologically relevant behaviours (female-female aggression, nest defence, exploration) and whether this is associated with differences in melanin-based plumage traits and investment in parental care. Solid integration within life history will be done by examining the link with life time fitness variation and telomere dynamics, a potential underlying proximate variable. At the end of this project I aim to have generated a better understanding of the costs and benefits associated with different female competitive phenotypes, and hence why they exist and how they are maintained.

Research team(s)

Abstract

To maximise survival and reproductive success, individuals are expected to optimise their foraging efficiency, which is influenced by several intrinsic (e.g., body condition) and extrinsic factors (e.g., fisheries discards and sea surface temperature). Additionally, many individuals have further optimised their foraging efficiency and became specialists, by using only a small niche of the broad spectrum. However, specialisation may limit the behavioural plasticity needed when conditions change. For central place foragers (CPF), who need to return to a specific location between feeding trips, the effects of environmental changes are likely to be more conspicuous. Therefore, I aim to determine the foraging efficiency of a CPF and measure how this foraging efficiency relates to among- and within-individual variation in foraging specialisation. I will investigate how foraging strategies change in function of intrinsic and extrinsic factors, and predict the effects of a changing environment on individual foraging efficiency. To accomplish this, I will perform aviary and field experiments with Lesser Black-backed Gulls, equipped with remote sensing devices that allow detailed measurements of movement dynamics. Data from these experiments will be assimilated with data on environmental conditions and resources, especially fisheries discards, to develop an individual-based foraging model that allows predicting the effects of rapid environmental change on foraging efficiency.

Researcher(s)

Research team(s)

Integrative and experimental study of the effects of artificial light exposure at night during development in birds in the real world: merging mechanistic approaches with short- and long-term health and fitness consequences.
01/01/2017
- 31/12/2020

Abstract

Artificial light at night (ALAN) has been underexplored as an anthropogenic stressor compared to chemical and noise pollution and it can be considered a threat to biodiversity. Because organisms have evolved with the periodicity of light dark cycles, ALAN may affect multiple aspects of behaviour and physiology. Changes in behaviour and physiology associated with ALAN may have particularly strong effects early in life, when developmental trajectories are sensitive to stressful conditions. Yet, a major gap in knowledge involves the effects of ALAN during development, particularly in natural populations. Using birds as a model, we will perform the first study to comprehensively examine how exposure to ALAN affects physiological stress in nestlings in the short- and long-term. We will examine whether early life light exposure affects aging rate, as indicated by telomere dynamics. Finally, we will assess whether exposure to ALAN early in life has enduring effects on the phenotype and fitness (reproduction, survival) of adults. We will use experimental approaches, involving manipulations of light inside nestboxes and cross-fostering experiments. We will also collect correlational data, using a population exposed to heterogeneous light regimes. By elucidating effects of ALAN on developing organisms and assessing mitigating strategies (such as part-night lighting), our study will motivate action to cope with the consequences of living in lighted environments.

Researcher(s)

Research team(s)

Genes and environment: on the interplay of nature and nurture.
01/10/2016
- 30/09/2021

Abstract

Over the past decade, birds have proven to be excellent models to study maternal effects, in particular hormone-mediated maternal effects, where offspring phenotype is influenced by maternally derived hormones deposited in the yolk. But although the effects of yolk hormones have been studied in great detail, virtually nothing is known about how hormone-mediated maternal effects influence fitness. In order to achieve this, it is highly important to study the effects of yolk hormones on offspring phenotype in different environments. Maternal effects are thought to serve first of all as an adjustment to current environmental conditions, and females alter the amount of yolk hormones deposited in response to environmental changes - via phenotypic plasticity. However, maternal effects have not only an environmental but also a genetic component, and both of which shape the evolutionary significance of a maternal effect. At current, there is still (too) little information available on heritable variation in maternal traits generating changes in offspring phenotype through variation in egg components.

Research team(s)

Abstract

Toxic pollutants increasingly threaten the integrity of natural populations. Metal pollution can have particularly detrimental effects on organisms and entire ecosystems. One potent means by which metal pollution may affect organisms is by elevating oxidative stress, resulting in biomolecular damage and fitness declines. However, the long-term behavioral and fitness implications of metal-induced oxidative stress are poorly understood. Using great tits (Parus major) as a model species, I propose to comprehensively explore how metal pollution affects oxidative stress, aging rate, behavior and fitness. I will perform the first study to examine whether metal-induced oxidative stress affects aging rate, on the molecular level as indicated by telomere degradation, and in terms of sexual signals and fitness traits. I will also explore effects of metal pollution on risk-taking behavior, which may be altered via effects of oxidative stress on neural function and life history decisions. I will study nest box populations of great-tits located across a metal pollution gradient. Experimental approaches will include exposing nestlings to metals and antioxidants, a parental risk-taking experiment, and measuring exploratory behavior in the laboratory. This study will make a pioneering contribution to evolutionary biology by testing the oxidative stress theory of aging in the context of metal pollution, and have critical importance to ecotoxicology and conservation biology.

Researcher(s)

Research team(s)

How conditional cooperation can be achieved to resolve the conflict between caring parents.
01/10/2016
- 30/09/2018

Abstract

Biparental care requires that two unrelated individuals raise their offspring together, which increases offspring survival and therefore parental fitness. However, each parent has to invest in care which comes with an individual cost and thus both parents aim to invest as little as possible. Recently, a parental strategy has been proposed that could provide a resolution for this conflict between the parents, that is taking turns in offspring provisioning, a form of cooperation that implies that parents alternate their feeding visits. However, some important aspects are still unknown, while vital for our understanding of the adaptive significance of this strategy. In particular, I aim to study (a) whether and how turn taking is an honest, evolutionary stable strategy; (b) how such a resolution of conflict between parents affects the parent-offspring conflict, as turn taking is thought to increase nest visit rates and thus offspring growth; (c) how turn taking can last, if parents may have to invest more heavily in another parental task besides provisioning; (d) how important compatibility between pair members is, and how such compatibility can be achieved; (e) and finally how the environmental conditions shape such parental strategy. To answer these questions, I will study a wild population of blue tits, a species with biparental care. I will use sophisticated tracking devices and cameras that allow detailed behavioural measurements, combined with well-designed experiments.

Researcher(s)

Research team(s)

Physiological stress as a mechanism underlying the effects of forest logging on tropical birds: an experimental approach.
01/10/2016
- 30/09/2018

Abstract

A key driver of land-use changes in tropical areas is commercial logging. Recent assessments of biodiversity have shown that there is a decrease of biodiversity in logged tropical forests, but also that there is large variation in how species are affected, indicating that some species are more vulnerable to logging than others. An important question then is which traits affect the species' capability to persist in degraded habitats. The answer to this might lie with the physiological mechanisms governing an organism's response to stressful stimuli. In this project, I will assess for the first time whether the capability to physiologically cope with stress is a mechanism driving the adaptive response of birds to the novel environmental conditions created by selective logging. To this end, I will carry out experimental investigations and comparative studies on birds in both unlogged (i.e., primary) and logged tropical forests of Borneo, a biodiversity hotspot severely impacted by selective logging. The complementary expertises of the (co-)promoters and the foreign collaborator and an established tropical field system with plots of both unlogged and logged forest guarantee the feasibility of my proposal.

Researcher(s)

Research team(s)

Short and long term effects of light pollution on the great tit (Parus major) and the effectiveness of mitigating strategies.
01/10/2016
- 30/09/2018

Abstract

Light pollution is likely to have a diverse and complex impact on individual animals. It can influence multiple biological systems simultaneously both directly and indirectly. The overall aim of this project is therefore to study the effects of light pollution and
emerging mitigating strategies (part-night and adaptive lighting) on songbirds (great tits) in an integrated way.

Research team(s)

Abstract

In this project, I therefore plan to investigate for the first time the relationships among environmental changes, stress hormones (corticosterone), oxidative stress, immune cell counts and herpes virus infections, using nestling Magnificent frigatebirds living on the Ile du Grand Connétable as my model system.

Abstract

Perfluoroalkyl acids (PFAAs) are substances which have been produced for more than five decades. Their unique properties of repelling both water and oil, make them suitable for many industrial and consumer applications such as water and dirt repellents for cloths and carpets, active components in firefighting foams or precursors in Teflon® production. Its extended use, together with their high persistence, resulted in a global contamination of the environment, wildlife and even humans. This ubiquity contrasts sharply with the limited information about their effects on organisms. With this study I will contribute to finding answers to fill some of the most important knowledge gaps in the toxicity mechanisms of these compounds. For this purpose, I will use two model bird species; great tits (Parus major) and canaries (Serinus canaria). Firstly, I will study the PFAAs exposure levels and the fitness consequences in free-living great tits along a PFAAs gradient from a fluorichemical plant in Antwerp, Belgium. Secondly, I will reproduce the exposure levels in captive canaries in order to replicate the results, found in the field, in a more controlled environment. The studied biomarkers will cover several levels of biological organization; from cellular to population response. As a result of the study, the PFAAs toxicity mechanisms will be better understood and their impact at an individual and population level can be more accurately forecast.

Researcher(s)

Research team(s)

The ecological significance of developmental stress: how early life experiences shape a resistant phenotype.
01/10/2016
- 31/12/2016

Abstract

A major challenge for ecologists and evolutionary biologists is in understanding how organisms will face the ongoing environmental changes. A hitherto unconsidered route whereby organisms adjust their phenotype to their environment is through early life priming to stressful conditions. Although the importance of early life priming in ageing research is increasingly advocated, we lack experimental studies that test whether early life priming of stress responses improves resilience to later life stress exposure and whether this results in organisms better able to reproduce. In this project, I propose to examine experimentally for the first time whether early life priming to oxidative stress increases the capacity of individuals to withstand oxidative stress later in life, whether this early life priming increases lifetime reproductive success and whether this early life priming offsets any detrimental effects of maternal age on the offspring. This innovative project that integrates state of the art developments in ecology and physiology will be of key importance to develop models and to set new standard metrics to assess and predict the responses of natural animal populations to a changing world.

Research team(s)

Abstract

Parents who raise their offspring are nowadays no longer considered as harmoniously interacting family members, but rather as entities being involved in an arms race shaped by underlying evolutionary conflicts of interest. Although parents temporarily cooperate to enhance offspring survival, each parent can gain extra benefits by transferring the largest workload to the partner. Parents thus need to negotiate about their investment to reach optimal cooperation. However, it is currently unclear how such negotiation can contribute to evolutionary stable levels of care. In fact, contradicting assumptions and predictions pile up among theoretical studies, which is largely due to a lack of empirical knowledge about how the negotiation process develops throughout a reproductive event. The aim of this proposal is therefore to cover the expenses of a re-usable transponder-reader system, in order to fill and bridge this knowledge gap via carefully designed experimental manipulations in our blue tit study population near Antwerp. Such a transponder-reader system is easy to apply and particularly useful to gather extremely detailed information about male and female provisioning strategies. This purchase would create a tremendous complementary benefit to my planned research. Together, the transponder-reader system will significantly increase our knowledge about the mechanisms that lead to sexual conflict (and its resolution) and set the stage for the next generation of theoretical negotiation models explaining evolutionary stability of biparental care.

Researcher(s)

Research team(s)

Abstract

Families in which two parents raise their offspring are currently no longer seen as a harmonious unit. They rather represent a battleground shaped by evolutionary conflicts of interest among its members that are not perfectly related. This is particularly true for parents. Although parents temporarily cooperate to enhance offspring survival, each parent can gain extra benefits by transferring the largest workload to the partner. Parents thus need to negotiate about their investment to reach optimal cooperation. However, it is currently unclear how such negotiation can contribute to evolutionary stable levels of care. This is largely due to a lack of empirical knowledge about (1) how the negotiation process develops throughout a reproductive event, (2) sex differences in the costs and benefits of negotiation and (3) potential physiological constraints on cooperation. The aim of this proposal is to fill and bridge these knowledge gaps via carefully designed experimental manipulations of parental exploitation opportunities, sexual conflict intensity and family structures. Meanwhile, I will include a proximate view to examine the extent to which hormone profiles constrain negotiated levels of care. Taken together, this proposed research will significantly increase our knowledge about the mechanisms that lead to conflict resolution and set the stage for the next generation of theoretical negotiation models explaining evolutionary stability of biparental care.

Research team(s)

Abstract

Parental care is a widespread phenomenon among the animal kingdom. It increases offspring survival, but entails fitness costs for the parents too. The resulting trade-off between investing in current offspring or in self-maintenance is a central tenet of life-history theory. But the costs and benefits of any parental decision will not be constant, but vary with multiple environmental factors. When adjusting their level of investment, parents therefore respond to cues from their ecological and social environment. Phenotypic plasticity, the ability of an individual to alter trait expression in function of the environment, plays logically a central role during parental care.
However, the ability to respond may under some circumstances be confounded. Individuals may for example differ in their foraging specialization, which impinges on their flexibility in parenting via an interdependence of behavioral consistency across different traits ("personality"). Moreover, the optimal parental decision will not only depend on the individual itself, but also on (its response to) the contribution to care by its partner. Parental responsiveness during this reciprocal interplay is thus likely to affect the efficiency of cooperation within pairs, and ultimately reproductive success. The reciprocal interplay in the debate over care, however, makes the coadaptation of corresponding traits possible (via indirect genetic effects), as has been shown in the context of parent-offspring communication. Such coadaptation may in turn impose limitations on the expression and evolution of individual behavioral traits - representing another important component for our understanding of the evolutionary ecology and stability of parental care.
This multidimensional complexity of parental care is fascinating and highly relevant, given the importance of parental care for the expression and development of ecologically important traits. It can best be studied by applying the recently developed behavioral reaction norm concept, which allows to partition phenotypic variance and to subsequently identify the adaptive significance of individual differences in (behavioral) variance components.

Research team(s)

Abstract

The aim of this project is to study condition-dependence of song and mate choice in canaries (Serinus canaria). So far, experimental studies have focussed on the effect of environmental quality in order to study condition dependence, in particular in the context of the 'developmental stress hypothesis'. The main focus of this study will be on (a) the effect of genetic condition on the expression of song and (b) the consequences of genetic quality for female mate choice.

Research team(s)

Abstract

Parental care increases offspring survival, but comes at a cost for the parents. Parents are
therefore presented with a trade-off between increased investment in current offspring and
resource allocation into self-maintenance and future reproductive success. Thus to optimise their
reproductive decisions, parents have to take numerous factors into account that relate to their
own intrinsic capacity as well as to aspects of their social and ecological environment. With my
research I aim to increase our understanding of (1) how reproductive decisions are related to
environmental variation in food availability and food accessibility. In particular, I want to study
whether and how individual specialisation in resource use constraints parents to comply their
offspring's need; (2) how individual decisions depend on the partner, and how efficient withinpair
coordination and equality in reproductive investment is achieved to ultimately maximise
reproductive success; (3) how intrinsic changes, such as occur in the context of senescence,
influence reproductive strategies - via changes in foraging performance and residual reproductive
value. To answer these questions, I will study a wild population of individually marked Lesser
black-backed gulls, a long-lived migratory seabird species with a high level of inter-individual
variation in resource use. I will make use of state-of-the-art GPS devices that allow detailed
measurements of parental effort and parental decision rules.

Researcher(s)

Research team(s)

Fly with the wind. Foraging behaviour and ecology of Antarctic fulmarine petrels in relation to wind and habitat characteristics
01/02/2015
- 31/12/2015

Abstract

Global climate change will lead to dramatic reductions in polar sea-ice and will additionally change wind conditions. I will study the foraging behaviour of four species of sea-ice associated Antarctic fulmarine petrels in response to environmental characteristics and specifically determine the effect of wind on flight decisions and flight costs in response to the species' morphology, taking advantage of a natural experiment.

Researcher(s)

Research team(s)

Effects of light pollution on behavioural, life-history and physiological traits in a songbird: an integrative approach.
01/01/2015
- 31/12/2018

Abstract

Light at night (LAN) is likely to have diverse and complex impacts on individual animals. It can influence multiple biological systems simultaneously both directly and indirectly. Therefore the overall aim of this project is to study the effects of LAN on songbirds in an integrated way. Great tits (Parus major) are highly suited to address our objectives.

Researcher(s)

Research team(s)

Abstract

The main objective of this quantitative genetic study is to evaluate the existence of genetic correlations within individuals, between individuals and between sexes, as well as the potential for correlational selection on suites of traits. I will use a captive canary (Serinus canaria) population to compare several repeated physiological and behavioural measurements between full-siblings
(brothers and sisters) and relate these estimates to their reproductive success.

Research team(s)

Abstract

The aim of the proposed project is to study the space use strategies, foraging behaviour and diet of an assembly of four petrels during the breeding season in two regions within Eastern Antarctica. A major focus will be on the identification of habitat requirements within the two distinct regions and the effects of wind speed and wind direction on the space use decisions and flight costs of the different species.

Researcher(s)

Research team(s)

Short and long term effects of light pollution on the great tit (Parus major) and the effectiveness of mitigating strategies.
01/10/2014
- 30/09/2016

Abstract

Light pollution is likely to have a diverse and complex impact on individual animals. It can influence multiple biological systems simultaneously both directly and indirectly. The overall aim of this project is therefore to study the effects of light pollution and
emerging mitigating strategies (part-night and adaptive lighting) on songbirds (great tits) in an integrated way.

Research team(s)

Abstract

In this project, I therefore plan to investigate for the first time the relationships among environmental changes, stress hormones (corticosterone), oxidative stress, immune cell counts and herpes virus infections, using nestling Magnificent frigatebirds living on the Ile du Grand Connétable as my model system.

Researcher(s)

Research team(s)

Oxidative stress as a constraint and cost of reproduction
01/02/2014
- 31/12/2014

Abstract

Oxidative stress has been proposed as one potential cost and constraint of reproductive investment. However, we lack yet clear experimental demonstrations of the link between oxidative stress and reproduction. This project will address the hypothesis that high parental effort in chick-rearing increases parental oxidative stress and reduces survival or future investment in reproduction. Captive canaries will be used as model species.

Researcher(s)

Research team(s)

Abstract

Senescence, the progressive deterioration of performance with advancing age, is increasingly documented in natural animal populations. The main research focus has been on the age-related decline of physiological traits and components of reproductive success, the latter typically measured as the number of offspring raised to independence. However, offspring number is only one component of reproductive success while offspring quality may also change as a function of parental age. The existence of such phenotypic changes is inferred from parental-age effects on offspring recruitment and longevity. Thus variation in offspring phenotype with parental age has significant fitness consequences, but very little is known as to why offspring from older parents may have decreased survival prospects.
In the proposed project we, therefore, shift the focus on transgenerational aspects of ageing to improve our understanding of the evolutionary ecology of senescence. We will study different pre- and postnatal pathways, to investigate how they may impinge on offspring development, whether these different mechanisms possibly counterbalance each other or to what extent they act in concert. To this end, we will combine sophisticated cross-fostering experiments in the field with cross-sectional, longitudinal and state-of-the-art behavioural tracking approaches. This project is only feasible as we can make use of a unique, long-term study population of individually marked Lesser black-backed gulls.

Research team(s)

Abstract

The central aim of my research project is to study how females may shape the phenotype of their offspring via the deposition of MAb into eggs, and how this maternal deposition is affected by their own body, physiological and immunological conditions (later referred to as female phenotypic quality).
I will first examine the transfer of MAb from the mother to the eggs. Second, I will look at the effects of these MAb on the physiology, humoral immunity, growth and survival of the embryos and chicks. Finally, I will also examine the potential role of corticosterone, the main avian stress hormone, on these mechanisms. To this end, a combination of correlative and
experimental approaches will be used.

Researcher(s)

Research team(s)

Oxidative stress as a constraint and cost of reproduction.
01/10/2013
- 30/09/2016

Abstract

In this project, I propose to address the following hypotheses using the canary (Serinus canaria) and the great tit (Parus major) as model species: prereproductive oxidative stress reduces subsequent reproductive investment; high parental effort in chick-rearing increases parental oxidative stress and reduces survival or future investment in reproduction; oxidative stress experienced during incubation reduces subsequent investment in chick-rearing. To this end, I will use a combination of experiments that will manipulate the pre- or post-laying oxidative stress level or the oxidative stress induced by chick-rearing effort.

Research team(s)

Abstract

The aim of this project is to study condition-dependence of song and mate choice in canaries (Serinus canaria). So far, experimental studies have focussed on the effect of environmental quality in order to study condition dependence, in particular in the context of the 'developmental stress hypothesis'. The main focus of this study will be on (a) the effect of genetic condition on the expression of song and (b) the consequences of genetic quality for female mate choice.

Researcher(s)

Research team(s)

Conflict and co-adaptation: the evolution of parental care in a wild bird species.
01/10/2013
- 30/09/2015

Abstract

Interactions between caring parents and their offspring are one of the most widespread social behaviours in animals. These parent-offspring interactions involve two parties and its evolution is, therefore, dependent on the evolution of two traits, parental provisioning and offspring begging. From a quantitative genetic perspective both behaviours should co-adapt, which should ultimately lead to (genetic) co-variation. But evidence for co-adaptation, its underlying genetics and the potential fitness consequences is as yet very limited, especially in natural populations. To test predictions of the co-adaptation hypothesis I make use of wild blue tits (Cyanistes caeruleus)

Researcher(s)

Research team(s)

Impact of ocean temperatures on the breeding ecology and phenology of rockhopper penguins.
01/10/2013
- 30/09/2014

Abstract

The aim of this study is to investigate how environmental variability (measured as SST) across several years affects the
condition of the same individual females and their timing of egg laying as well as their reproductive investment.
I expect to find such effects as SST should affect the prey availability in general (through the availability of nutrients)
and the timing of the peak in prey availability in special.
As SST are expected to increase in the course of climate change, my study could help to understand the effects and
identify successful strategies to adapt to environmental changes.

Researcher(s)

Research team(s)

Can changes in climate and in flame retardant exposure over time alter the levels of the stress hormone corticosterone in white-tailed eagles (Haliaeetus albicilla)?
01/02/2013
- 30/04/2013

Abstract

The ban on the use of PBDEs in Europe has resulted in the increased use of alternate flame retardants (FRs),
such as HBCD, TBBPA, BTBPE and organophosphorus FRs. In this project, temporal trends of both regulated
and emerging FRs will be investigated, making use of a feather collection of white tailed sea eagles (Haliaeetus albicilla) since 1969. Furthermore, we aim to study interactions between climate variations and temporal trends of FRs on the stress hormone concentrations in feathers of the white-tailed eagles. Measuring pollutants and stress hormones simultaneously in feathers of individual birds is a novel approach that will allow understanding of how environmental variability may contribute to variation in stress response.

Abstract

The main aim of this project is to study the impact of interactions between natural stressors and anthropogenic stress, caused by environmental contamination with OHCs, on the health of nestling birds of prey in (sub)Arctic regions. Birds of prey from (sub)Arctic regions have several characteristics that make them very useful to study OHC exposure in combination with natural stressors (see methodology).

Researcher(s)

Research team(s)

Evolutionary ecological perspectives on bird family life: A study into the genetic and phenotypic mechanisms of offspring begging.
01/10/2012
- 30/09/2016

Abstract

Begging, the solicitation of food from parents by as yet dependent offspring, forms a trait with direct and significant consequences on growth, survival, and thus ultimately on fitness. Obviously, begging for food from parents should elicit the transfer of resources, typically a greater amount than parents are selected to provide, since parents and offspring are, at least in birds, not genetically identical. When offspring seeks parental investment, their begging exerts a selective pressure on parental provisioning. But begging is at the same time also target of selection, because it is influenced by the parental response. Both behaviors should, therefore, ultimately become co-adapted. Being agent and target of selection, begging follows a complex evolutionary trajectory, which is additionally flavoured by the evolutionary conflict over parental investment.
From this it becomes clear that it requires detailed information on both selection and inheritance of begging in order to understand its evolutionary potential. A very powerful quantitative genetic tool to study genetic mechanisms and evolutionary processes is to impose artificial selection upon the trait of interest, here begging. Artificial selection not only allows to identify the pattern of inheritance, but also to investigate genetic covariances and correlated responses in traits that generate trade-offs or that are co-adapted. This opens the possibility to test important evolutionary ecological predictions for instance in the context of evolutionary conflicts of interest and the honest signaling of offspring need. The use of artificial selection is also suitable to identify underlying control mechanisms via a correlated selection on physiological traits. Physiological mechanisms have the potential to affect or even constrain the response to selection by linking the expression of different traits and by generating trade-offs across contexts or life-history stages. Studying the phenotypic mechanisms such as the regulating role of testosterone is, therefore, necessary and will complement the research into the genetic mechanisms. Ultimately, the combined information will help to understand what mechanisms make begging adaptive and thus improve our understanding of the evolutionary ecology of life-history traits and fitness components.

Research team(s)

Abstract

The evolution of parental care is central to our understanding of among other social systems and sexual selection, which are main areas of research in evolutionary biology. However, virtually nothing is known about its genetic architecture. Parental care includes complex parent-offspring interactions and its evolution therefore depends on the evolution of two traits, parental provisioning and offspring begging. Both behaviours should ultimately become genetically correlated, since changes in one trait exert a selective pressure on the evolution
of the other. To complicate matters, the evolution of parental care is also shaped by a conflict of interest over the degree of provided parental investment between parents and offspring. My proposed research project aims at studying the genetic basis and consequences of co-adaptation between parental provisioning and offspring begging. In a first step, I will separately look at the heritability and phenotypic plasticity of both, parental provisioning and offspring begging, which set the basis for any co-evolutionary process. Next, I will focus on
the co-variance of both traits using an intra-individual and an intra-family approach. Finally, I will study the functional consequences of co-adaptation for both parents and offspring, which will also improve our understanding of who is winning the parent-offspring conflict.

Researcher(s)

Research team(s)

Abstract

The general aim of the proposal is to test if the supplementation of carotenoids and/or cholesterol can promote the synthesis of T that regulate the uptake of carotenoids in the cells of the trait. This is in line with the finding that carotenoids can regulate the steroidogenic activity in humans (Wickenheisser et al. 2005; Angwafor and Anderson 2008) and other mammals (Folman et al. 1983; Chew 1993; Chew et al. 2001; Campbell et al. 2006). Indirect evidence shows that providing zebra finches Taeniopygia
guttata with carotenoids enhances their escape flight ability (Blount and Matheson 2006), suggesting that carotenoids may stimulate the production of androgen with anabolic effects on the flight muscles. Similar evidence comes from a recent discovery that European starlings Sturnus vulgaris supplemented with carotenoids increase their song rate and that starlings supplemented with both carotenoids and T show an enhanced nest-oriented song compared to birds treated just with T (VanHout, Eens and Pinxten 2011). Moreover providing cholesterol to zebra finches enhances bill carotenoids (McGraw and Parker 2006) suggesting a promotion of T by cholesterol is the first step of the complex steroidogenic process.

Abstract

The main aim of the proposed research is to study exposure and effects of organic pollutants in predatory birds, using the white-tailed eagle (Haliaeetus albicilla; WTE) as a model species. The proposed research can be subdivided in several objectives.
Firstly, I will study exposure through the development of physiologically based pharmacokinetic (PBPK) bioaccumulation models. Since a high amount of species-specific information is required to develop such a model, I have chosen the WTE as a model species. This species has been monitored for years through international collaborations and I have access to databases providing sufficient information for the first objective (see methodology). The second objective aims to study the effects from the physiological up to the population level. The last objective deals with the study of exposure to organic pollutants in the light of varying climate and feeding conditions over time.

Researcher(s)

Research team(s)

We are chemistry, development of educational materials and packages for chemistry teachers in the second stage of secondary education.
01/07/2012
- 30/09/2013

Abstract

This project represents a formal research agreement between UA and on the other hand the Province of Antwerp. UA provides the Province of Antwerp research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

Research team(s)

A quantitative genetic approach to study the mechanisms and functions of bird song.
01/01/2012
- 31/12/2015

Abstract

Using a pedigreed captive canary population, the proposed project applies a quantitative genetic approach to the mechanisms and function of bird song, a trait playing an important role in the study of sexual selection. We will estimate the genetic inheritance of bird song as well as potential environmental influences. In order to test predictions of evolutionary theory in the context of sexual
selection, we will investigate whether bird song indicates genetic and/or environmental quality, and analyze genetic correlations among song parameters, condition and immunocompetence. Finally, we apply a quantitative genetic approach to the endocrine regulation of corticosterone and testosterone, as the evolution of the traits studied here may depend on indirect selection on the
underlying mechanisms.

Researcher(s)

Research team(s)

Art and the evolution of signalling in a cultural species: a comparative approach.
01/01/2012
- 31/12/2015

Abstract

This project aims to tackle some pending philosophical, psychological and biological isues with regard to art by combining research methods from these different domains. The following questions will be addressed. (1) Is there a deep similarity between human art and "artistic" behaviour in animals or are the observed similarities only superficial? (2) To what extent can signalling theory - a body of theoretical work within evolutionary biology examining communication between individuals - make precise predictions about art systems or traditions? (3) Can applying signalling theory to art shed new light on authenticity, a long-standing problem in
the philosophy of art?

Researcher(s)

Research team(s)

Show me your colour, I will tell you your quality
01/01/2012
- 31/12/2012

Abstract

While body colour can provide important information about animal health, relatively little is known about the relationships between female colour, egg colour and health status. We propose to investigate the relationship between the colour of the body parts of female birds and their individual quality, and between the colour of eggs and their composition. We aim to use colour measurement as a non-invasive method to access bird and egg qualities.

Research team(s)

Abstract

Song in songbirds as a model system for studying complex behaviours: an integration of ecological, physiological and neurobiological data in an evolutionary framework [and also Causes and consequences of variation in complex secondary sexual song characteristics: a longitudinal and multidisciplinary approach by integrating behavioural, physiological and molecular data.

Researcher(s)

Research team(s)

Genes and environment: on the interplay of nature and nurture.
01/10/2011
- 30/09/2016

Abstract

Over the past decade, birds have proven to be excellent models to study maternal effects, in particular hormone-mediated maternal effects, where offspring phenotype is influenced by maternally derived hormones deposited in the yolk. But although the effects of yolk hormones have been studied in great detail, virtually nothing is known about how hormone-mediated maternal effects influence fitness. In order to achieve this, it is highly important to study the effects of yolk hormones on offspring phenotype in different environments. Maternal effects are thought to serve first of all as an adjustment to current environmental conditions, and females alter the amount of yolk hormones deposited in response to environmental changes - via phenotypic plasticity. However, maternal effects have not only an environmental but also a genetic component, and both of which shape the evolutionary significance of a maternal effect. At current, there is still (too) little information available on heritable variation in maternal traits generating changes in offspring phenotype through variation in egg components.

Researcher(s)

Research team(s)

Conflict and co-adaptation: the evolution of parental care in a wild bird species.
01/10/2011
- 30/09/2013

Abstract

Interactions between caring parents and their offspring are one of the most widespread social behaviours in animals. These parent-offspring interactions involve two parties and its evolution is, therefore, dependent on the evolution of two traits, parental provisioning and offspring begging. From a quantitative genetic perspective both behaviours should co-adapt, which should ultimately lead to (genetic) co-variation. But evidence for co-adaptation, its underlying genetics and the potential fitness consequences is as yet very limited, especially in natural populations. Furthermore, co-adaptation is not the only process shaping the evolution of parental care. Its evolution is also affected by a conflict of interest over the amount of parental care, since offspring is selected to seek greater parental investment than the
parents are selected to give. In my PhD-project I will integrate approaches from behavioural ecology and quantitative genetics to study: (a) the (genetic) correlation between offspring solicitation and parental provisioning genes in a natural population of blue tits (b) the potential fitness consequences of a disruption of this correlation for both parents - in the light of the sexual conflict over parental care (c) whether maternal effects play a role in shaping the co-evolution of offspring solicitation and parental provisioning."

Researcher(s)

Research team(s)

Vocal behaviour of the great tit.
01/10/2011
- 30/09/2012

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university.

Research team(s)

Abstract

Mothers can influence the phenotype and performance of their offspring by adjusting their deposition of egg components to environmental conditions and according to their own physiological state. Birds, and rockhopper penguins (Eudyptes chrysocome) in particular, have excellent characteristics which can be used to study the sources of variation in maternal investment in eggs and their potential effects on embryonic survival and development. Rockhopper penguins exhibit a reversed egg size dimorphism, brood reduction, a unique reversed hatching asynchrony, and large differences in breeding success among years and populations. Therefore, I can study variation in maternal investment on all possible levels: within the population, within clutches and among seasons and populations. I will first explore the sources of variation in investment in eggs (in terms of laying
date, mass, and levels of androgens, carotenoids and antibodies) according to female quality (e.g. arrival and laying dates and weights, blood parameters). Various approaches will be used to examine the contribution of male quality. Effects on embryo survival and development will be studied mainly via experimental manipulation of androgen levels. Finally, my long-term study and collaboration with groups working on other rockhopper populations will enable assessment of inter-annual and populational variation in maternal investment.

Research team(s)

Abstract

A lot of research has already been performed on the function of maternal hormones in the eggs of birds. The observed effects have however always been described independently of the environment the birds live in, although an effect might be positive in one environment while being negative in another. This makes the environment an essential factor in this research topic. In addition, studies so far have mainly been done from the chicks' point of view. Nevertheless, what is positive for the parents does not necessarily need to be positive for the young, and vice versa. Despite this, the effects on the parents have received little attention and need to be studied in greater detail. Combining these two main principles, the adaptive value of maternal hormone deposition can only be determined in this broader context, with environment-dependent hormone deposition possibly being a mothers' optimal strategy to maximise her fitness.

Researcher(s)

Research team(s)

The role of oxytocin and vasopressin as a proximal basis for (pro)social behaviour: inter- and intraspecific comparison of bonobo (Pan paniscus) and chimpanzee (Pan troglodytes).
01/12/2010
- 30/11/2014

Abstract

This project represents a formal research agreement between UA and on the other hand KMDA. UA provides KMDA research results mentioned in the title of the project under the conditions as stipulated in this contract.

Research team(s)

Abstract

In this study we examine maternal yolk hormones in the budgerigar (Melopsittacus undulatus), which give the female the ability to modify offspring phenotype to their future environment. We study the variation of maternal yolk hormones within and between clutches. We search evidence for possible mechanism of variable hormone deposition in the yolk and we study the effects of variable deposition for the offspring, in the short term as well as in the long term.

Research team(s)

Abstract

The evolution of parental care is central to our understanding of among other social systems and sexual selection, which are main areas of research in evolutionary biology. However, virtually nothing is known about its genetic architecture. Parental care includes complex parent-offspring interactions and its evolution therefore depends on the evolution of two traits, parental provisioning and offspring begging. Both behaviours should ultimately become genetically correlated, since changes in one trait exert a selective pressure on the evolution
of the other. To complicate matters, the evolution of parental care is also shaped by a conflict of interest over the degree of provided parental investment between parents and offspring. My proposed research project aims at studying the genetic basis and consequences of co-adaptation between parental provisioning and offspring begging. In a first step, I will separately look at the heritability and phenotypic plasticity of both, parental provisioning and offspring begging, which set the basis for any co-evolutionary process. Next, I will focus on
the co-variance of both traits using an intra-individual and an intra-family approach. Finally, I will study the functional consequences of co-adaptation for both parents and offspring, which will also improve our understanding of who is winning the parent-offspring conflict.

Research team(s)

Abstract

The main focus of this project is to asses the signal value of carotenoid colouration in relation to oxidative stress levels and diet quality in the great tit (Parus major). The great tit has a carotenoid based signal, namely the yellow breast colour. The brightness of this colour is linked to the condition and the quality of the bearer. The research will be conducted in a well known metal pollution gradient. We expect that birds in polluted areas will fade under the influence of metal induced oxidative stress and/or lower food quality.

Researcher(s)

Research team(s)

Causes and consequences of variation in complex secondary sexual song characteristics: a longitudinal and multidisciplinary approach by integrating behavioural, physiological and molecular data.
01/01/2010
- 31/12/2013

Abstract

During this project we aim to study, in an integrated manner, the causes and consequences of variation in a wide range of song characteristics in the great tit. By utilising automatic song recording systems, we will register and quantify all possible aspects of the song of at least 200 free-living great tits in full detail. We aim to monitor as many males as possible during their life time. The unique dataset obtained in this way will be used for further cross-sectional and longitudinal analyses. We will study the causes and consequences in song behaviour in an integrated way by using physiological, immuno-endocrine, and state-of-the-art molecular techniques, as well as personality and learning tests and heredity analyses.

Researcher(s)

Research team(s)

Causes and consequences of variation in complex secondary sexual song characteristics: a longitudinal and multidisciplinary approach by integrating behavioural, physiological and molecular data.
01/01/2010
- 31/12/2013

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university.

Abstract

Recently, the intensive use of the brominated flame retardants hexabromocyclododecane (HBCD) and tetrabromobishenol A (TBBPA) has lead to their ubiquitous presence in the environment. Information about their levels and potential effects is thus of major importance. Birds have been used as a succesful biomonitor since the 1960s. In this project, we will make use of raptors to study geographical patterns and tissue distribution of HBCD and TBBPA.

Research team(s)

The influence of testosterone and stress on the song development and song expression in adult male starlings.
01/01/2010
- 31/12/2011

Abstract

This project represents a research agreement between the UA and on the onther hand IWT. UA provides IWT research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

Research team(s)

Abstract

The central aim of this postdoc research project is to examine the sources of variation in maternal investment in eggs of rockhopper penguins (Eudyptes chrysocome) and potential effects of such investment on embryonic survival an development. We will study this variation at all possible levels: within the breeding population (i.e. among clutches), within clutches and among breeding seasons and different population.

Abstract

Researcher(s)

Research team(s)

A study of the functional role of the male hormone testosterone in female vertebrates.
01/01/2009
- 31/12/2010

Abstract

The main focus of this project is to asses what the effects are of testosterone (T) on the morphology, physiology and behaviour in the female great tit (Parus major) and in the end on their fitness. Additionally I will investigate if T-concentrations in females are a consequence of a correlated response on T-concentrations in males. At the end of this project I will integrate my results with the current literature on T in female birds. By combining the results of these studies we can generate higher order of conclusions on the relationship between T and behavioural, physiological and morphological parameters.

Researcher(s)

Research team(s)

Abstract

A lot of research has already been performed on the function of maternal hormones in the eggs of birds. The observed effects have however always been described independently of the environment the birds live in, although an effect might be positive in one environment while being negative in another. This makes the environment an essential factor in this research topic. In addition, studies so far have mainly been done from the chicks' point of view. Nevertheless, what is positive for the parents does not necessarily need to be positive for the young, and vice versa. Despite this, the effects on the parents have received little attention and need to be studied in greater detail. Combining these two main principles, the adaptive value of maternal hormone deposition can only be determined in this broader context, with environment-dependent hormone deposition possibly being a mothers' optimal strategy to maximise her fitness.

Research team(s)

Abstract

The research objectives are
- Examine the factors that determine concentrations of organic pollutants in feathers;
- Study the relationship between levels of organic pollutants and effects in individual birds;
- Assess sources of geographical variation for contamination with organic pollutants using feathers;
- Integrate all results to resolve which factors explain variation in contamination among bird species.

Researcher(s)

Research team(s)

Abstract

Brominated fire retardants (BFRs) are a large group of chemicals which are widely used in different materials (e.g. electronics, textile). There is however a lack of information on the toxicological profile of these pollutants. The aims of this research project are to study 1) maternal transfer, 2) reproductive, behavioural and health effects and 3) toxicokinetics and metabolism of brominated fire retardants (BFRs). To accomplish these objectives, both experimental and field studies will be performed in different songbird species.

Research team(s)

Abstract

In this study we examine maternal yolk hormones in the budgerigar (Melopsittacus undulatus), which give the female the ability to modify offspring phenotype to their future environment. We study the variation of maternal yolk hormones within and between clutches. We search evidence for possible mechanism of variable hormone deposition in the yolk and we study the effects of variable deposition for the offspring, in the short term as well as in the long term.

Research team(s)

Abstract

The main focus of this project is to asses the signal value of carotenoid colouration in relation to oxidative stress levels and diet quality in the great tit (Parus major). The great tit has a carotenoid based signal, namely the yellow breast colour. The brightness of this colour is linked to the condition and the quality of the bearer. The research will be conducted in a well known metal pollution gradient. We expect that birds in polluted areas will fade under the influence of metal induced oxidative stress and/or lower food quality.

Researcher(s)

Research team(s)

On the function of maternal yolk androgens in birds: from early adjustments to post-hatching conditions to long-term effects.
01/07/2008
- 31/12/2012

Abstract

The effects of maternal hormones in birds are thought to represent examples of so-called maternal effects and are thought to have evolved to translate the environmental conditions experienced by the mother into adaptive phenotypic variation of the offspring. Their adaptive significance is therefore likely to depend on the post-hatching conditions, but long-lasting changes in offspring phenotype need to be considered too.

Abstract

The aim of this project is to address gaps in our understanding of intraspecific variation in animal behaviour, especially the movement behaviour of small bentic freshwater fish species. To achieve this, the proposed study integrates two closely-linked research components.

Researcher(s)

Research team(s)

Abstract

Male ornaments are thought to indicate heritable male quality. Females selecting males with elaborated ornaments thereby select males that can afford to invest in their ornaments, e.g. because they are best adapted to the current conditions. Male ornaments have also been hypothesized to indicate the early developmental history of an individual. However, how females integrate the different types of information in mate choice is largely unknown.

Research team(s)

Abstract

The main focus of this project is to asses the signal value of carotenoid colouration in relation to oxidative stress levels and diet quality in the great tit (Parus major). The great tit has a carotenoid based signal, namely the yellow breast colour. The brightness of this colour is linked to the condition and the quality of the bearer. The research will be conducted in a well known metal pollution gradient. We expect that birds in polluted areas will fade under the influence of metal induced oxidative stress and/or lower food quality.

Researcher(s)

Research team(s)

The consequences of host-parasite co-evolution for sexual selection and life history: studies from two evolutionary points of view.
01/10/2007
- 31/03/2009

Abstract

The objectives of the project are to investigate (i) the effect of malaria prevalence on sexual signalling; (ii) the potential physiological and genetic mechanisms that are responsible for the maintenance of reliable signalling of parasite levels; (iii) the interspecific relationship between disease risk and mating system using primates and birds; and (iv) the evolutionary relationship between parasite and host life history traits by focusing on the perspective of malaria parasites.

Research team(s)

Abstract

The expression of secondary sexual characteristics is often an honest signal of the condition of the male. In this project, the relationship will be studied between the expression of secondary sexual characteristics in the great tit (Parus major) and oxidative stress levels (caused by exposure to metal pollution). The amount of genetic and environmental variation on oxidative stress and secondary sexual characteristics will be estimated with a cross-fostering experiment.

Abstract

Researcher(s)

Research team(s)

Deceptive signals? On the function of maternal yolk hormones in family conflict.
01/10/2006
- 31/12/2008

Abstract

The identification of the costs and benefits that shape the relationship between male attractiveness and maternal yolk androgen deposition is the aim of this project at the Department of Biology-Ethology of the University of Antwerp. These costs may be borne by the female (who may have to expose herself to high levels of androgens), the male (who are potentially deceived by the female since yolk androgen deposition could play an important role in the sexual conflict over parental care) or the offspring (who may be affected by costs of embryonic hormone exposure depending on its genetic quality). I will investigate proximate aspects of the maternal hormone deposition, look at the relationship between genetic and maternal effects, in particular through long-term studies, and address the question whether maternal yolk hormones mediate family conflicts.

Researcher(s)

Research team(s)

Study of occurrence of persistent organic pollutants in several bird species, with special attention to the development of non-destructive methods for biomonitoring.
01/10/2006
- 30/09/2008

Abstract

Human activities have lead to the release and worldwide distribution of various hazardous substances, such as heavy metals and persistent organic pollutants (POPs). Growing concern about possible harmful effects of these pollutants has encouraged the development of several biomonitoring programs. At the moment there is a lack of scientific data concerning (1) the occurrence of many pollutants in biota and (2) the usefulness of various bird species as a bio-indicator species. However, such research is necessary regarding birds and other animal groups.
In my project, I will assess the concentrations of various heavy metals and POPs in internal tissue samples, feathers, blood samples and eggs of different bird species. Relatively little information is available about concentrations of recent POPs, such as PBDEs (fire retardants) and PFOS in terrestrial vertebrate animals (including birds) in Flanders. Moreover no comparative studies have investigated the usefulness of different bird species as a biomonitor of pollution with POPs and heavy metals. Brief, I will investigate whether there are differences in contamination between study areas, whether non-invasive biomonitoring methods (i.e. feathers) can be developed and whether differences in contamination levels between bird species of the same area can be related tot different feeding strategies, ecology, territory size etc. Finally, I will integrate the results of the different examinations to determine which bird species appear to be the most suitable biomonitors for both types of pollutants.

Researcher(s)

Research team(s)

The role of the 'male' sex hormone testosterone in female vertebrates: an integrated study using the great tit and the European starling as model species.
01/07/2006
- 31/12/2010

Abstract

The aim of this project is to investigate the role of the 'male' sex hormone testosterone (T) in female vertebrates. This will be accomplished by (1) studying the effects of experimentally elevated T levels on behavioural, reproductive and physiological parameters in female great tits and European starlings in natural and controlled experimental conditions and (2) investigating to which extent T-sensitive parameters affect female fitness.

Researcher(s)

Research team(s)

Deceptive signals ¿ on the function of maternal yolk hormones in family conflict.
01/03/2006
- 31/12/2007

Abstract

This project addresses the question whether the deposition of maternal yolk hormones in birds plays a critical role in the parental tug-of-war over the contribution to offspring care. Because offspring begging, which is at the heart of this family conflict, is influenced by maternal yolk hormones, it is to be expected that maternal hormones modulate this family conflict. Thus females may attempt to manipulate their partner through the transfer of hormones into the egg.

Research team(s)

Abstract

Information on the movement behaviour of freshwater fishes with no commercial value, especially benthic species, is still very limited. The aim of this study is to eliminate this lacuna, in particular for the bullhead (Cottus gobio). Both direct (capture-mark-recapture, telemetry) and indirect (genetic markers) methods will be used to obtain this goal. Such an integrated approach is scientifically very relevant and innovative.

Research team(s)

Abstract

Oxidative stress in organisms results in the peroxidation of all major biomolecules, such as DNA, proteins and lipids. The most frequently used method to determine oxidative stress is to quantify lipid peroxidation with the thiobarbituric acid reactive substances (TBARS) method. In this study a method will be developed and validated to quantify TBARS in feathers of birds.

BOF/IWT research fellowship.
01/01/2006
- 31/12/2006

Abstract

Researcher(s)

Research team(s)

Abstract

In this project we examine the relative importance of a great variety of characteristics (song, personality, colour and plumage characteristics, morphological characteristics) in the context of mate choice and intrasexual competition. Furthermore, we will invest whether females invest more in reproduction if they are mated to an attractive partner (assessed by secondary sexual characters). We will examine whether females adapt the deposition of maternal hormones in their eggs in function of the quality of their mate.

The effects of lead on avian sperm quality with special reference to the possible role of oxidative stress.
01/10/2005
- 31/12/2007

Abstract

Research team(s)

Study of the role of carotenoids in oxidative stress, immunocompetence and the expression of secondary sexual characteristics with particular attention to possible trade-offs among these different physiological functions : a multidisciplinary approach.
01/01/2005
- 31/12/2008

Abstract

The scope of this proposal is to study in an integrated and compre- hensive manner the role of carotenoids in all 3 above mentioned physiological functions (antioxidative potential, immuno-stimulation and expression of secondary sexual characteristics), with special attention on the possible trade-off among the different physiological functions of carotenoids. In concrete, we will study the mitigable effect of carotenoids on the amount and the effects of lead-induced oxidative stress in birds. Special attention will be given to the pos- sibility that the allocation of carotenoids as antioxidants may influ- ence the other functions of carotenoids. This proposal will thus contribute significantly to the study of carotenoid-based sexual traits as honest signals of condition and health status in birds and other vertebrates. Finally, we will investigate whether interspecific differ- ences in susceptibility to lead poisoning are caused by differences in antioxidant levels among species, which has recently been suggested.
The objectives of our proposal will be met with experiments under laboratory and natural conditions. In the field study, great tits will be used as model species. Because great tits readily use nest boxes, they can be easily manipulated and studied. Janssens et al. (2003a) have found that great tits are susceptible to heavy metal poisoning, which resulted in an impaired reproductive success. Finally, the great tit is one of the few bird species in which a conspicuous carotenoid- based coloration is developed already during the nestling stage, which arises from unmodified deposition of lutein and zeaxanthin (fschirren et al., 2003). These characteristics render the great tit a very suitable study species. Because great tits are difficult to study in laboratory conditions however, we will use the zebra finch (T aeniopygia guttata) as model species in the laboratory experiments. This small passerine is an important study species in behavioural ecological research and has been used previously by ETHOL to investigate the accumulation of lead in tissues and feathers (Dauwe et al. 2002, Snoeijs et al., in prep.)

Bird song and parasites : study of the relationship between a complex communication system and immune function using experimental and comparative methods.
01/10/2004
- 30/09/2007

Abstract

Researcher(s)

Research team(s)

Effects of environmental pollutants on the sperm quality and the reproductive success of birds : an experimental study.
01/10/2004
- 30/09/2007

Abstract

Human impact on the environment has increased dramatically over the last decades. The technological and industrial development has resulted in the release of numerous hazardous substances into the environment, which in many cases have been distributed worldwide. The occurrence of contaminants in the environment poses a genuine threat to the quality of ecosystems and the organisms that live there (Merian 1997). Although a wide variety of chemicals have been detected in environmental samples, environmental chemistry is still virtually limited to two major classes of chemicals, the heavy metals and the poly halogenated aromatic hydrocarbons (PHAHs; PeakalI1992). The exposure to contaminants can result in negative effects at all levels of biological organisation: from a biQchemical I response to a decrease in population numbers. Although effects on molecular or cellular level are in many cases easily i detectable and often have a clear dose-response relationship, the ecological relevance is often very low. Effects of pollutants on individual or population level on the other hand, have a much higher ecological significance. Especially the impairment of normal reproduction is very important from an ecological point of view. Moreover, because successful reproduction requires the integration of endocrine, physiological and behavioural processes, it is very sensitive to pollution. In recent years concern about the effect of environmental changes on male reproductive health has grown to become a major preoccupation in some developed countries (Tieleman et al. 1999, Telisman et al. ,2000, Hauser et al. 2002). Sperm quality may be a rapid-measurement endpoint biomarker for measuring sublethal effects of chemical pollutants on reproduction (Boyle et al. 1992, Citutovic et al. 1993). Because a reduction in sperm quality does not have to result in an impaired reproductive success, sperm quality may function as an early warning system (Bonde et al. 1999). Studies on the effects of pollutants, both spermatotoxic chemicals and endocrine disruptors, on the sperm quality of mammals have increased markedly. Although several studies have shown that PHAHs and heavy metals may negatively affect sperm quality in mammals (Apostoli et al. 1998), few studies however have examined the effects of contaminants on avian §perm. In behavioural ecological studies and in poultry research a number of techniques have been developed and used to determine the sperm quality of birds non-invasively. An interesting, indirect measure of sperm quality is the number of spermatozoa in the perivitelline layer (membrane surrounding the yolk) of the egg (Birkhead 1989, Wishart 1997). Recently we have shown in a field study that heavy metal pollution can have a negative effect on the number of spermatozoa in blue tit (Parus caeruleus) eggs (Dauwe et al. 2004). In the framework of this proposal, this technique will be evaluated in more detail as a possible non-destructive indicator for the effects of contaminants on the sperm quality and the reproductive success. To do so, all factors that may have an influence on the number of spermatozoa in the egg will be studied. The possible effect of a reduced sperm quality on the re~roductive success (hatching success) will also be assessed. In this study we will use the zebra finch (Taeniopygia guttata) as model species, because they can be studied and bred relatively easily in captivity. Moreover, the zebra finch has been used intensively as model species in physiological, neurobiological and behavioural research (Scheuhammer 1996, Zann 1996). Finally, the number of spermatozoa in zebra finch eggs have already been used to determine sperm quality in numerous studies on sperm competition in birds (see Birkhead 1989). To meet the objectives of this proposal, the effect of lead and PCB 153 on the sperm quality of zebra finches will be studied. We have chosen for these two pollutants because they are among the most widespread and

Researcher(s)

Research team(s)

Study of occurrence of persistent organic pollutants in several bird species, with special attention to the development of non-destructive methods for biomonitoring.
01/10/2004
- 30/09/2006

Abstract

Human activities have lead to the release and worldwide distribution of various hazardous substances, such as heavy metals and persistent organic pollutants (POPs). Growing concern about possible harmful effects of these pollutants has encouraged the development of several biomonitoring programs. At the moment there is a lack of scientific data concerning (1) the occurrence of many pollutants in biota and (2) the usefulness of various bird species as a bio-indicator species. However, such research is necessary regarding birds and other animal groups.
In my project, I will assess the concentrations of various heavy metals and POPs in internal tissue samples, feathers, blood samples and eggs of different bird species. Relatively little information is available about concentrations of recent POPs, such as PBDEs (fire retardants) and PFOS in terrestrial vertebrate animals (including birds) in Flanders. Moreover no comparative studies have investigated the usefulness of different bird species as a biomonitor of pollution with POPs and heavy metals. Brief, I will investigate whether there are differences in contamination between study areas, whether non-invasive biomonitoring methods (i.e. feathers) can be developed and whether differences in contamination levels between bird species of the same area can be related tot different feeding strategies, ecology, territory size etc. Finally, I will integrate the results of the different examinations to determine which bird species appear to be the most suitable biomonitors for both types of pollutants.

Researcher(s)

Research team(s)

An integrated study on the effects of persistent organochlorine pollutants (POPs) in insectivorous songbirds, with special attention to their possible endocrine disrupting role.
01/01/2004
- 31/12/2007

Abstract

Researcher(s)

Research team(s)

A study of the influence of sexual selection and interspecific competition on the size and compostion of the Blue Tit song repertoire.
01/01/2004
- 31/12/2005

Abstract

Blue Tits (Parus caeruleus), as many other bird species, show great geographic variation in song from northern Europe to the Mediterranean region, North Africa and the Canary Islands. For example, Blue Tit repertoire size (the number of different song types per individual) differs noticeably among populations and ranges from 3 to 19 song types. In the north, songs that include a trill (a series of rapidly repeated notes) are widespread, whereas trills are rare in southern Spain and Corsica and have never been reported in North Africa and the Canary Islands. This variation in repertoire size and repertoire composition might be the result of geographic variation in local selection pressures. Possible selection pressures are sexual selection among Blue Tits and interspecific competition with a close competitor, the Great Tit (Parus major). Since both species are able to produce sounds with a similar syntax (non-trills) and frequency range, acoustic competition between these species could have caused a shift in Blue Tit song syntax. By using trills (of different syntax), Blue Tits can avoid the problem of being misidentified by Great Tits and therefore trilled song might reduce the probability of energy-demanding, aggressive territorial interactions with the more dominant Great Tits. Song variation could also be the result of sexual selection. Many bird species use different songs for inter 'and intrasexual communication and repertoire size may be related to the intensity of sexual selection or population density. In this study we will investigate whether trills and non-trills have different functional meanings, whether there is a relationship between repertoire size and the intensity of sexual selection, whether acoustic competition between Blue and Great Tits exists and whether there is a problem of misidentification between both species. In order to address these questions, different experiments will be performed in various populations (in Belgium and southern Spain) that differ in repertoire size and Great Tit density. Integration of the obtained behavioural, hormonal and morphological data will help to reveal the factors responsible for the origin and maintenance of song diversity among Blue Tit populations and might reveal important insights into Blue Tit communication strategies.

Researcher(s)

Research team(s)

Abstract

Secondary sexual characteristic give signals about individual quality to potential mates- 'good genes' hypothesis. In the last years there is a growing interest in studies concerning evolution of secondary sexual traits in female species. In the literature there are more and more evidence signifying that the mate choice may not be limited to the female, but may occur bilaterally. Furthermore it has been suggested that secondary sexual traits in females can have an adaptive value.
This research aims at better understanding of the function of secondary sexual traits in female individuals. It focuses particularly on song behavior in female starlings, which until now has not been studied in detail, and explores its endocrine and neurobiological basis. The study gives attention to the seasonal and individual variation in female song activity. By investigating the relationships between song characteristics (song complexity and/or song frequency) and other characteristics (immunocompetence, weight, timing of pair formation and clutch size) this research provides a better view at the adaptive significance of variation in female song behavior. Preliminary results suggest that female song in this species might be used as an honest signal advertising quality.

Song as a model system to study secondary sexual characters in a comparative evolutionary context.
01/10/2003
- 30/09/2004

Abstract

Researcher(s)

Research team(s)

Study of the occurrence of several types of pollutants in birds, with special attention to differences between trophic levels and study areas.
01/10/2003
- 30/09/2004

Abstract

Various hazardous substances, such as heavy metals and persistent organic pollutants (POPs), have been released into the environment, as a consequence of human activities and have been distributed worldwide. Growing concern about possible harmful effects of these pollutants has lead to the development of several biomonitoring programs. At the moment there is a lack of scientific data concerning (1) the occurrence of many pollutants in biota and (2) the usefulness of various bird species as bio-indicator species, although such research is necessary regarding birds and other animal groups.
In my project, I will assess the concentrations of various heavy metals and POPs in internal tissue samples, feathers, blood samples and eggs of different bird species who live in the same study area, but vary in food preferences, ecology, territory size, body size ' Samples will be collected in two different study areas: one urban and highly polluted area (Hoboken-Wilrijk) and one rural area (presumably Peer).
I will investigate whether there are differences in contamination between the two study areas, whether non-invasive biomonitoring methods can be developed, whether differences in contamination levels between bird species of the same area can be related tot different feeding strategies, ecology, territory size' and whether relations exist between concentrations of pollutants and biomarker responses. Finally, I will examine which bird species appear to be the most suitable biomonitors for both types of pollutants.

Researcher(s)

Research team(s)

Study on the accumulation and effects of lead on birds : an experimental study with the zebrafinch as modelspecies.
01/10/2003
- 30/09/2004

Abstract

In this study, the accumulation of lead in a small passerine songbird, the zebra finch, will be investigated. Special attention will be paid to the use of non-destructive techniques (e.g. eggs and feathers) to determine the exposure to lead. Also the effects of lead on reproductive behaviour and success of the zebrafinch will be investigated. Apart from general reproductive parameters, such as clutch size and hatching success, the effect of lead on sperm quality will also be assessed.

Research team(s)

Abstract

In thus study intrasexual and intersexual behavioural reproductive strategies of chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) will be studied in captivity and compared. On the other hand, the physiology of sperm production will be studied in both species. This will be useful to understand the differences in social organization of the of the two species.

Researcher(s)

Research team(s)

Testing the resource of allocation hypothesis in small passerines.
01/10/2002
- 30/09/2004

Abstract

Several models of sexual selection predict that females choose males of high quality, an attribute that can be inherited by their offspring wich in turn enhances their survival (good genes models), on the basis of secondary sexual traits. However, over the years, it has been difficult to define this quality. In 1982, Hamilton and Zuk (1982) proposed that the resistance to infections and diseases (immunocompetence) could be used by females to choose a mate. For a few years now, possible tradeoffs between the individual immune system and fitness related traits like reproductive efforts and secondary sexual traits (ecological immunology) have become also more of interest.

Researcher(s)

Research team(s)

Maternal styles and infant development in bonobos (Pan paniscus) en chimpanzees (Pan troglodytes): a study of intra- and interspecific variation in relation to differences in social organization.
01/02/2002
- 31/01/2004

Abstract

In many primates, the mother is the primary caretaker. A mother, who can balance her investment in such a way as to promote her infant's independence without jeopardizing its survival, will deplete her energy reserves less en will be able to start reproducing within a shorter period of time. How much a mother will invest in her offspring will depend upon her age, dominance position and parity. Other factors that can influence maternal behaviour are the sex of the offspring and the absence or presence of siblings. Apart from these individual factors, species-specific characteristics of the social organization and mating system of a species will influence maternal behaviour.
Although the mother-infant bond is the primary social relationship among primates, research on the relation between social organization, mating system and maternal behaviour on the one hand and the relation between maternal behaviour and development of infants on the other, is rare. To gain more insight concerning female reproductive strategies in primates, research on intra- and interspecific variation of maternal behaviour and investment is necessary. Two species that lend themselves perfectly for this research are the bonobo (Pan paniscus) and the chimpanzee (Pan troglodytes).
Behavioural observations will allow us to determine the maternal styles and follow the development of behaviour of bonobo and chimpanzee infants. More specifically we will investigate the relation between the ontogeny of behaviour and the maternal style. The influence of individual varying factors of the mothers and the species-specific characteristics of the two Pan-species on maternal behaviour or style will be investigated. The data will be used to test the hypothesis that interspecific differences in maternal styles are an adaptive response to differences in social organization. Additionally, studbook analyses (ex. calculation of birth sex ratios, interbirth intervals, mortality and survival of infants) will allow us to compare the reproductive success and reproductive strategies of female bonobos and chimpanzees.

Researcher(s)

Research team(s)

Abstract

Male secondary sexual behaviours have been the focus of intensive research. By contrast, the evolution of secondary sexual behaviours in females has received little attention. This project tries to get a better understanding of the function of secondary sexual behaviours (song and aggressive behaviour) in female starlings Sturnus vulgaris and will study their importance in intra-sexual rivalry and in mate choice by males. The endocrine and neurobiological basis of song behaviour in females will also be studied.

Researcher(s)

Research team(s)

A study of the influence of sexual selection and interspecific competition on the size and compostion of the Blue Tit song repertoire.
01/01/2002
- 31/12/2003

Abstract

Blue Tits (Parus caeruleus), as many other bird species, show great geographic variation in song from northern Europe to the Mediterranean region, North Africa and the Canary Islands. For example, Blue Tit repertoire size (the number of different song types per individual) differs noticeably among populations and ranges from 3 to 19 song types. In the north, songs that include a trill (a series of rapidly repeated notes) are widespread, whereas trills are rare in southern Spain and Corsica and have never been reported in North Africa and the Canary Islands. This variation in repertoire size and repertoire composition might be the result of geographic variation in local selection pressures. Possible selection pressures are sexual selection among Blue Tits and interspecific competition with a close competitor, the Great Tit (Parus major). Since both species are able to produce sounds with a similar syntax (non-trills) and frequency range, acoustic competition between these species could have caused a shift in Blue Tit song syntax. By using trills (of different syntax), Blue Tits can avoid the problem of being misidentified by Great Tits and therefore trilled song might reduce the probability of energy-demanding, aggressive territorial interactions with the more dominant Great Tits. Song variation could also be the result of sexual selection. Many bird species use different songs for inter 'and intrasexual communication and repertoire size may be related to the intensity of sexual selection or population density. In this study we will investigate whether trills and non-trills have different functional meanings, whether there is a relationship between repertoire size and the intensity of sexual selection, whether acoustic competition between Blue and Great Tits exists and whether there is a problem of misidentification between both species. In order to address these questions, different experiments will be performed in various populations (in Belgium and southern Spain) that differ in repertoire size and Great Tit density. Integration of the obtained behavioural, hormonal and morphological data will help to reveal the factors responsible for the origin and maintenance of song diversity among Blue Tit populations and might reveal important insights into Blue Tit communication strategies.

Abstract

Researcher(s)

Research team(s)

Integrating molecular techniques with field observations in the study of sexual selection in birds.
01/01/2001
- 31/12/2003

Abstract

In this project we will use molecular techniques to study reproductive behaviour of birds. In the framework of ongoing sexual selection research, we will determine the exact reproductive success of birds using microsatellites, and we will study factors that influence the sex ratio within a clutch.

Researcher(s)

Research team(s)

Abstract

In this project, mechanistic (proximate) and ultimate aspects of sexual selection are integrated and insights and techniques from different disciplines are incorporated to get to know more about the development of secondary sexual characters and the selective forces which may have led to their evolution

Researcher(s)

Research team(s)

The use of bird feathers as bio-indicators for heavy metal pollution and study of the effect of this pollution on reproduction and health status.
01/01/2000
- 31/12/2004

Abstract

In recent years, bird feathers have been used as an indicator tissue of metal exposure in birds. Bird feathers are ideal for assessment of heavy metals because they accumulate certain heavy metals in proportion to blood levels at the time of feather formation. Studying the effect of heavy metals on terrestrial songbirds by integrating reproductive, endocrinological, immunological and behavioural parameters is innovating.